AU612977B2 - Transmitter/receiver apparatus - Google Patents
Transmitter/receiver apparatus Download PDFInfo
- Publication number
- AU612977B2 AU612977B2 AU73306/87A AU7330687A AU612977B2 AU 612977 B2 AU612977 B2 AU 612977B2 AU 73306/87 A AU73306/87 A AU 73306/87A AU 7330687 A AU7330687 A AU 7330687A AU 612977 B2 AU612977 B2 AU 612977B2
- Authority
- AU
- Australia
- Prior art keywords
- frequency band
- transmit
- receive
- frequency
- transmitter
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
- 230000010355 oscillation Effects 0.000 claims description 21
- 238000004891 communication Methods 0.000 description 7
- 238000002955 isolation Methods 0.000 description 6
- 230000005540 biological transmission Effects 0.000 description 2
- 241000981595 Zoysia japonica Species 0.000 description 1
- 238000010276 construction Methods 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 238000000034 method Methods 0.000 description 1
- 238000013508 migration Methods 0.000 description 1
- 230000005012 migration Effects 0.000 description 1
- 230000000644 propagated effect Effects 0.000 description 1
Classifications
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04B—TRANSMISSION
- H04B1/00—Details of transmission systems, not covered by a single one of groups H04B3/00 - H04B13/00; Details of transmission systems not characterised by the medium used for transmission
- H04B1/38—Transceivers, i.e. devices in which transmitter and receiver form a structural unit and in which at least one part is used for functions of transmitting and receiving
- H04B1/40—Circuits
- H04B1/50—Circuits using different frequencies for the two directions of communication
Landscapes
- Engineering & Computer Science (AREA)
- Computer Networks & Wireless Communication (AREA)
- Signal Processing (AREA)
- Radio Relay Systems (AREA)
- Transceivers (AREA)
- Cable Transmission Systems, Equalization Of Radio And Reduction Of Echo (AREA)
- Superheterodyne Receivers (AREA)
- Transmitters (AREA)
- Input Circuits Of Receivers And Coupling Of Receivers And Audio Equipment (AREA)
Description
I1 6129 7 SPRUSON FERGUSON FORM 10 COMMONWEALTH OF AUSTRALIA PATENTS ACT 1952 COMPLETE SPECIFICATION
(ORIGINAL)
FOR OFFICE USE: ?3 c' 061 7 Class Int. Class Complete Specification Lodged: Accepted: Published: Priority: Related Art: Name of Applicant: Address of Applicant: Actual Inventor: Address for Service: Complete Specification NEC Corporation 33-1, Shiba 5-chome, Minato-ku, Tokyo, Japan OSAMU YAMAMOTO Spruson Ferguson, Patent Attorneys, Level 33 St Martins Tower, 31 Market Street, Sydney, New South Wales, 2000, Australia for the invention entitled: "TRANSMITTER/RECEIVER APPARATUS" The following statement is a full description of this invention, including the best method of performing it known to us SBR/JS/0075T i- TRANSMITTER/RECEIVER APPARATUS Background of the Invention The present invention relates to a transmitter/ receiver apparatus having application to microwave band communications such as satellite communication and, more particularly, to a transmitter/receiver apparatus which is miniature enough to be installed in, for example, the feeder section of an antenna.
While the tendency to apply satellite communication channels to commercial communications is increasing, a 1 0 prerequisite for facilitating such an application is °o cutting down the cost and size of a transmitter/receiver apparatus. For example, a miniature transmitter/receiver apparatus which can be incorporated in the feeder section of an about 2 meters antenna is desired.
In a transmitter/receiver apparatus applicable to commercial communications which uses a microwave band, satellite communication, while the transmit level is on the order of 1 watt, the receive level is more than 100 dB lower than the transmit level. Hence, what is very important with this type of transmitter/receiver apparatus is setting up sufficiently isolation between discrete circuits in order to minimize interference from a transmit system to a receive system. However, in the case that miniaturization is intended presupposing the overall "I A Ad W Y L- I A1 -2dimensions of the apparatus housing, the freedom of circuit layout is so limited that the sufficient isolation between independent circuits is impracticable.
SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a miniature and inexpensive transmitter/receiver apparatus which is satisfactorily applicable to microwave band communications even if the isolation between discrete circuits is insufficient.
According to one aspect of the present invention there is disclosed a transmitter/receiver apparatus comprising a first and a second device which are interconnected by a single signal cable; said first device comprising: a local oscillator for generating a local oscillation frequency at a predetermined position between a transmit and a receive frequency band; a transmit frequency converter connected to said local oscillator for converting a transmit intermediate frequency band into said transmit frequency band based on said local oscillation frequency such that a transmit image frequency band of said transmit frequency band does not overlap said receive frequency band; a receive frequency converter connected to said local oscillator for converting, based on the local oscillation frequency, the receive frequency band into a receive intermediate frequency band, which does not overlap the transmit intermediate frequency band, such that a receive image frequency band of said receive intermediate frequency band does not overlap the transmit frequency band, said frequency converter and said receive frequency converter being disposed separately from said local oscillator; and a first frequency multiplexer connected between one end of the signal cable and said transmit and receive frequency converters for multipIexlng in frequency a signal of the transmit intermediate frequency band and a signal of the receive intermediate frequency band; and said second device comprising: a second frequency multiplexer connected to the other end of said signal cable; and a demodulator and a modulator each being connected to a respective one of other two terminals of said second frequency multiplexer, HRF/0440y ~Ad 3 -3- The transmitter/receiver apparatus further comprises a frequency multiplexer which connects to the transmit and receive frequency converters a single cable over which a signal of the transmit intermediate frequency band and a signal of the receive intermediate frequency band are propagated in a frequency-multi .exed condition.
The local oscillator generates a local oscillation frequency at a position between a transmit frequency band and a receive frequency band and which is commonly applied to transmission and receipt, the local oscillation frequency being fed to the transmit and receive frequency converters.
The transmit frequency converter converts a transmit Sintermediate frequency band into the transmit frequency band based on the local oscillation frequency and such that its transmit image frequency band does not overlap the receive frequency band.
Further, the receive frequency converter converts, based on the local oscillation frequency, the receive frequency band into a receive intermediate frequency band, which does not overlap the transmit intermediate frequency band, such that its receive image frequency band does not overlap the transmit frequency band.
As a result, the receive intermediate frequency band, the transmit intermediate frequency band, the transmit image frequency band, the receive frequency band, the local oscillation frequency, the receive image frequency 4 band, and the transmit frequency band are distribute& on a frequency axis without overlapping each other.
The frequency multiplexer connects a single signal cable to the transmit and receive frequency converters, multiplexes an incoming signal of the transmit intermediate frequency band and an outgoing signal of the receive intermediate frequency band, and allows intermediate frequency signals to be interchanged over the single signal cable.
Thus, in the transmitter/receiver apparatus of the present invention, the receive intermediate frequency band, the transmit intermediate frequency band, the transmit image frequency band, the receive frequency band, the local oscillation frequency, the receive image frequency band, and the transmit frequency band are so determined as not to overlap each other. Hence, interference due to migration from the transmit system to the receive system and others is eliminated even if the isolation between independent circuits is insufficient, whereby the transmitter/receiver apparatus is rendered simple and miniature. The transmit and receive systems share a single local oscillator to cut down the cost of the apparatus, compareA to a prior art apparatus in which they are provided with an exclusive local oscillator each. Further, since a single signal cable suffices for the interchange of intermediate frequency signals, the cable and construction expenses are noticeably reduced. Hence, there can be implemented easily and 5 zr;rsn ;irr~siL economically an arrangement wherein, for example, the apparatus of the present invention is mounted in an outside antenna feeder section and connected to an indoor main equipment by a single signal cable.
Brief Description of the Drawings Fig. 1 is a block diagram of a transmitter/receiver apparatus embodying the present invention; Fig. 2 is a view of a frequency distribution; and Fig. 3 is a side elevation showing the apparatus of Fig. 1 which is installed in the feeder section of an antenna by way on example.
Detailed Description of Preferred Embodiment Referring o Fig. 1 of the drawings, a transmitter/ receiver apparatus in accordance with the present invention is shown and generally designated by the reference numeral 100. The apparatus 100 has a miniature box-like configuration and may be mounted in, for example, the feeder section of an outdoor antenna i. Basically, the apparatus 100 comprises a local oscillator 2, a duplexer 3, a low noise amplifier 4, a receive frequency converter 5, a transmit frequency converter 6, a power amplifier 7, and a frequency multiplexer 8. The frequency multiplexer 8 is connected by a single signal cable, e.g., a coaxial cable 9 to a frequency multiplexer 10 of indoor main equipment 101. Connected to the frequency multiplexer _Ii i I-i-~bl- LL_ L L -L-i 6are a demodulator 11 and a modulator 12.
The local oscillator 2 oscillates a local oscillation frequency LO at a predetermined position between a transmit frequency band T and a receive frequency band R. The local oscillation frequency LO is fed to the transmit and receive frequency converters 6 and 5. Specially, assuming that the transmit frequency T lies in a range of 14.0 to 14.5 GHz and the receive frequency R in a range of 11.7 to 12.2 GHz by way of example, the local oscillation frequency LO is preselected to be 12.7 GHz.
A signal modulated by the modulator 12 and whose frequency lies in a transmit intermediate frequency band TIF is fed to the transmit frequency converter 6 via the frequency multiplexer 10 of the indoor equipment 101, the signal cable 9, and the frequency multiplexer 8. The transmit frequency converter 6 converts the input signal having the frequency T into a signal which belongs to the transmit frequency band T, based on the local oscillation frequency LO such that its transmit image frequency TIMG does not overlap the receive frequency band R. The signal with the frequency T is amplified by the power amplifier 7 and, then, radiated from the antenna 1 toward a satellite.
In this particular embodiment, the transmit intermediate frequency band TIP ranges from 1.3 to 1.8 GHz while the transmit image frequency band TIMG ranges from 10.9 to 11.4 GHz.
L -3 I~ -J diLI*- 7 A signal coming in through the antenna 1 and lying in the receive frequency band R is routed through the duplexer 3 and low noise amplifier 4 to the receive frequency converter 5. This converter 5 converts, based on the local oscillation frequency LO, the signal of the receive frequency band R into a signal whose frequency lies in a receive intermediate frequency band RIF, which does not overlap the transmit intermediate frequency band TIF, such that its receive image frequenii', band RIMG does not overlap the transmit frequency band T. The output of the receive frequency converter 5 is delivered to the indoor equipment 101 via the frequency multiplexer 8, signal cable 9, and frequency multiplexer 10. In this particular embodiment, the receive intermediate frequency band RIF ranges from 0.5 to 1.0 GHz, and the receive image frequency band RIMG ranges from 13.2 to 13.7 GHz.
Fig. 2 shows the consequent distribution of frequencies which are generated in the transmit and receive systems of the transmitter/receiver apparatus 100. As shown, the receive intermediate frequency band RIF (0.5 to 1.0 GHz),the transmit intermediate frequency band TIF (1.3 to 1.8 GHz), the transmit image frequency band TIMG (10.9 to 11.4 GHz) the receive frequency band R (11.7 to 12.2 GHz), the local oscillation frequency LO (12.7 GHz), the receive image frequency band RIMG (13.2 to 13.7 GHz) and the transmit frequency band T (14.0 to 14.5 GHz) are sequentially 8arranged on the frequency axis without overlapping each other.
In short, the present invention implements a transmit and a receive system with a common local oscillation source and, thereby, cuts down the cost, compared to a case wherein two independent local oscillation sources are used.
Since different intermediate frequency bands are adopted for transmission and receipt, interference from the transmit system to the receive system is eliminated even if the isolation between discrete circuits is incomplete, as would occur if a transmit/receive apparatus were installed in a small housing. Furthermore, that the transmit image frequency band does not overlap the receive frequency band and the transmit image frequency band also protects the apparatus against interference. Consequently, a simple, miniature and inexpensive transmitter/receiver apparatus is achieved.
Since the transmit and receive intermediate frequencies are different from each other as stated above, intermediate frequency signals can be interchanged between the outdoor apparatus 100 and the indoor main equipment 101 over the single cable 9 by multiplexing signals which belong to those different frequency bands. Each of the frequency multiplexers 8 and 10 has a frequency multiplexing function and a signal interchanging function. Such allows the single cable 9 to suffice when the apparatus 100 is to be 1; -9placed outside of a building and connected to tho indoor equipment 101.
As shown in Fig. 3, the transmitter/receiver apparatus 100 is miniature enough to be installed even in, for example, the feeder section of an antenna and, therefore, easy to mount. Such remarkably cuts down the total cost of an antenna and others to which the apparatus 100 is applicable.
In Fig. 3, there are ,.,hown the cable, e.g. a coaxial cable 9 adapted to interconnect the outdoor transmitter/ receiver apparatus 100 and the indoor equipment 101, a primary radiator, or horn, 111 mounted on the apparatus 100, a parabolic reflector 112 of the antenna, support members 113 for supporting the apparatus 100, a framework 114 for supporting the whole antenna with the appratus 100, a mechanism 115 for adjusting the elevation of the antenna, and an antenna support post. Basically, the illustrative configuration constitutes an offset parabolic antenna. To align the'antenna pointing to a direction of wave arrival, the azimuth is adjusted by the post 116 and the elevation by the elevation adjusting mechanism 115.
For an arrangement relating to the present invention, a reference may be made to U.S. Patent Application (Serial No. 831,667) which is assigned to -the applicant of the present invention.
10 As described above, in a transmitter/receiver apparatus of the present invention, a receive intermediate frequency band, a transmit intermediate frequency band, a transmit image frequency band, a receive frequency band, a local oscillation frequency, a receive image frequency band, and a transmit frequency band are so determined as not to overlap each other. Hence, interference from a transmit system to a receive system and others is eliminated even if the isolation between independent circuits is insufficient, whereby the transmitter/receiver apparatus is rendered simple and miniature. The transmit and receive systems share a single local oscillator to cut down the cost of the apparatus, compared to a prior art apparatus in which they are providud with an exclusive local oscillator each.
Further, since a single signal cable suffices for the interchange of intermediate frequency signals, the cable and ceostruction expenses are noticably reduced. Hence, there can be implemented easily and economically an arrangement wherein, for example, the apparatus of the present invention is mounted in an outside antenna feeder section and connected to an indoor main equipment by a single signal cable.
Claims (4)
1. A transmitter/receiver apparatus comprising a first and a second device which are interconnected by a single signal cable; said first device comprising: a local oscillator for generating a local oscillation frequency at a predetermined position between a transmit and a receive frequency band; a transmit frequency converter connected to said local oscillator for converting a transmit intermediate frequency band into said transmit frequency band based on said local oscillation frequency such that a transmit image frequency band of said transmit frequency band does not overlap said receive frequency band; a receive frequency converter connected to said local oscillator for converting, based on the local oscillation frequency, the receive frequency band into a receive intermediate frequency band, which does not overlap the transmit intermediate frequency band, such that a receive image frequency band of said receive Intermediate frequency band does not overlap the transmit frequency band, said frequency converter and said receive frequency converter being dispo:ed separately from said local oscillator; and a first frequency multiplexer connected between one end of the signal cable and said transmit and receive frequency converters for multiplexing in frequency a signal of the transmit intermediate frequency band and a signal of the receive intermediate frequency band; and said second device comprising: a second frequency multiplexer connected to the other end of said signal cable; and a demodulator and a modulator each being connected to a respective one of other two terminals of said second frequency multiplexer.
2. A transmitter/receiver apparatus as claimed in claim 1, wherein the first device is located outside of a building and the second device inside of said building.
3. A transmitter/receiver apparatus as claimed in claim 1, wherein the first device is mounted in a feeder section of an antenna.
4. A transmitter/receiver apparatus as claimed in claim 1, wherein the sign)Ol cable comprises a coaxial cable. HRF/0440y L. i- -r i IC A. -d -12- A transmitter/receiver apparatus substantially as described with reference to che accompanying drawings. DATED this THIRD day of MAY 1991 NEC CORPORATION Patent Attorneys for the Applicant SPRUSON FERGUSON S HRF/0440y 'M<a ai
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP61118908A JPS62274934A (en) | 1986-05-23 | 1986-05-23 | Transmitter-receiver |
| JP61-118908 | 1986-05-23 |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| AU7330687A AU7330687A (en) | 1987-11-26 |
| AU612977B2 true AU612977B2 (en) | 1991-07-25 |
Family
ID=14748144
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| AU73306/87A Expired AU612977B2 (en) | 1986-05-23 | 1987-05-22 | Transmitter/receiver apparatus |
Country Status (5)
| Country | Link |
|---|---|
| US (1) | US4907291A (en) |
| EP (1) | EP0246658A3 (en) |
| JP (1) | JPS62274934A (en) |
| AU (1) | AU612977B2 (en) |
| CA (1) | CA1282877C (en) |
Families Citing this family (21)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS62274934A (en) * | 1986-05-23 | 1987-11-28 | Nec Corp | Transmitter-receiver |
| JPH0389721A (en) * | 1989-09-01 | 1991-04-15 | Oki Electric Ind Co Ltd | Transmitter/receiver |
| GB9025007D0 (en) * | 1990-11-16 | 1991-01-02 | Orbitel Mobile Communications | Mobile radio telephone |
| US5355524A (en) * | 1992-01-21 | 1994-10-11 | Motorola, Inc. | Integrated radio receiver/transmitter structure |
| JPH05300048A (en) * | 1992-04-14 | 1993-11-12 | Motorola Inc | Radio-frequency transmitter-receiver and its operating method |
| GB2272605B (en) * | 1992-11-11 | 1996-11-27 | Nokia Mobile Phones Uk | Radio frequency circuit for a time division multiple access system |
| US5369779A (en) * | 1993-06-28 | 1994-11-29 | Zenith Electronics Corp. | Two-way MMDS communications system |
| SE9302741D0 (en) * | 1993-08-25 | 1993-08-25 | Volvo Ab | Device for generating sound in vehicles |
| JP2809097B2 (en) * | 1994-04-26 | 1998-10-08 | 日本電気株式会社 | Radio station equipment |
| US5669067A (en) * | 1994-06-29 | 1997-09-16 | Harris Corporation | Remotely controllable variable intermediate frequency transceiver |
| GB2292502B (en) * | 1994-08-17 | 1998-07-15 | Continental Microwave Technolo | Microwave radio system |
| DE69605620T2 (en) | 1995-03-24 | 2000-06-08 | European Broadcasting Union, Grand-Saconnex | CONFERENCE SYSTEM |
| FI102121B (en) * | 1995-04-07 | 1998-10-15 | Filtronic Lk Oy | Transmitter / receiver for radio communication |
| JP3252653B2 (en) * | 1995-06-05 | 2002-02-04 | 三菱電機株式会社 | Transceiver |
| GB2325347B (en) | 1997-05-14 | 2002-07-17 | Internat Mobile Satellite Orga | Satellite communications apparatus and method |
| US6144473A (en) * | 1997-06-09 | 2000-11-07 | Sigmatel, Inc. | Method and apparatus for transceiving infrared signals |
| GB2331666A (en) | 1997-11-20 | 1999-05-26 | Dsc Telecom Lp | Subscriber Terminal for a Wireless Telecommunications System |
| US6141538A (en) * | 1998-03-03 | 2000-10-31 | Northrop Grumman Corporation | Transmit detection circuit |
| JP3107035B2 (en) * | 1998-03-18 | 2000-11-06 | 日本電気株式会社 | Low noise amplifier and its control circuit |
| US6711394B2 (en) | 1998-08-06 | 2004-03-23 | Isco International, Inc. | RF receiver having cascaded filters and an intermediate amplifier stage |
| US6314309B1 (en) | 1998-09-22 | 2001-11-06 | Illinois Superconductor Corp. | Dual operation mode all temperature filter using superconducting resonators |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0246658A2 (en) * | 1986-05-23 | 1987-11-25 | Nec Corporation | Transmitter/Receiver apparatus |
Family Cites Families (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2864944A (en) * | 1954-05-18 | 1958-12-16 | Rca Corp | Two way radio relay system including traveling wave tubes |
| CH477132A (en) * | 1968-10-15 | 1969-08-15 | Patelhold Patentverwertung | Transceiver for very high frequencies |
| JPS5380906A (en) * | 1976-12-27 | 1978-07-17 | Oki Electric Ind Co Ltd | Frequency converter |
| JPS6019173A (en) * | 1983-07-13 | 1985-01-31 | Fuji Xerox Co Ltd | Toner supply method of copying machine |
| JPS60149227A (en) * | 1984-01-13 | 1985-08-06 | Sony Corp | Shf receiver |
-
1986
- 1986-05-23 JP JP61118908A patent/JPS62274934A/en active Granted
-
1987
- 1987-05-19 US US07/052,001 patent/US4907291A/en not_active Expired - Lifetime
- 1987-05-22 AU AU73306/87A patent/AU612977B2/en not_active Expired
- 1987-05-22 EP EP87107488A patent/EP0246658A3/en not_active Withdrawn
- 1987-05-22 CA CA000537701A patent/CA1282877C/en not_active Expired - Lifetime
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0246658A2 (en) * | 1986-05-23 | 1987-11-25 | Nec Corporation | Transmitter/Receiver apparatus |
Also Published As
| Publication number | Publication date |
|---|---|
| AU7330687A (en) | 1987-11-26 |
| EP0246658A3 (en) | 1989-07-19 |
| JPH0466413B2 (en) | 1992-10-23 |
| CA1282877C (en) | 1991-04-09 |
| EP0246658A2 (en) | 1987-11-25 |
| US4907291A (en) | 1990-03-06 |
| JPS62274934A (en) | 1987-11-28 |
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